Made the Linux standalone builds more self-contained, now they include
their own linker and glibc, and ugly hacks to make them be used when
running the included programs. This should make them more portable
to older systems.

Set up an arm autobuilder.
This autobuilder runs in an Debian armel chroot, using
qemu-user-static (with a patch to make it support some syscalls ghc uses).
No webapp yet; waiting on feedback of how well it works. I hope this
build will be usable on eg, Synology NAS and Raspberry PI.

Also worked on improving the assistant's batching of commits during the
startup scan. And some other followups and bug triage.